50$ 6max AJ vs unknown opp on AA board

This shallow I dont see sense in flatting preflop from SB. I would only flat sometimes with like KK+ as trap versus right opponents. So either fold or shove preflop and shove would be default play versus CO open.

As played I would check-call flop and check-shove turn. Folding turn would be too weak as villain can be value betting lot of weaker hands and I think he is going to call shove with e.g. KT or better. Also some flush draws and perhaps KJ type of gutshots.

pre-flop is a huge leak, just shove pre.

as played c/shove turn

pre-flop is a huge leak, just shove pre.

The preflop call here is not my standard play but I figure calling and giving
the opponent the opportunity to make mistakes postflop makes it a fine play as
long as BB folds frequently.

Against a shove with AJ the opponent has only one quite easy decision.

Why do you think a shove is much better here than playing small ball flop poker against a player who is most likely not very advanced?

you have a value hand pre-flop = raise (especially when you are OOP and have a disadvantage post-flop)
if you raise you are committed = shove

I agree with this advice against regulars.
It's simple, effective and good for multitabling.
Against non-regulars I see even more value in playing flops with them against their full range.
The disadvantage being oop at these stack sizes vanishes quickly against players of a lesser calibre.